Wireless data communication is becoming increasingly popular and wireless data communication technology is being incorporated into numerous devices, such as cellular telephones, personal digital assistants, and wireless email devices, for example. Wireless data communication technology is also used in computer networks, thus allowing a user of a portable computer to move freely around an office, unencumbered by network wiring.
Two standard protocols for wireless data transmission are the IEEE 802.11a standard (IEEE std. 802.11a-1999, published December 1999) and the IEEE 802.11b standard (IEEE std. 802.11b-1999, published December 1999). Each of these protocols define multiple data transmission rates. IEEE 802.11a specifies a maximum transmission rate of 54 Mbits/s (megabits per second), with defined slower transmission rates of 48 Mbits/s, 36 Mbits/s, 24 Mbits/s, 18 Mbits/s, 12 Mbits/s, 9 Mbits/s, and 6 Mbits/s. IEEE 802.11b specifies a maximum transmission rate of 11 Mbits/s, with defined slower transmission rates of 5.5 Mbits/s, 2 Mbits/s, and 1 Mbit/s.
When maximum data throughput is desired, data is transferred at the highest data transmission rate available. Unfortunately, various factors, such as electrical interference, noise, and signal attenuation often limit that data transmission rate.